PCA9536 4-bit I²C-bus And SMBus I/O Port

The PCA9536 is an 8-pin CMOS device that provides 4 bits of General Purpose parallel
Input/Output (GPIO) expansion for I2C-bus SMBus applications and was developed to
enhance the NXP Semiconductors family of I2C-bus I/O expanders. I/O expanders provide
a simple solution when additional I/O is needed for ACPI Power SwitchesSensors
push buttons, LEDs fans, etc.
The PCA9536 consists of a 4-bit Configuration Register (input or output selection), 4-bit
Input Port Register 4-bit Output Port Register and a 4-bit Polarity Inversion Register
(active HIGH or active LOW operation). The system master CAN enable the I/Os as either
inputs or outputs by writing to the I/O configuration bits. The data for each input or output
is kept in the corresponding Input Port or Output Port Register The polarity of the read
RegisterCAN be inverted with the Polarity Inversion Register All RegistersCAN be read by the
system master.
The power-on reset sets the Registers to their default values and initializes the device state
machine.
The I2C-bus address is fixed and allows only one device on the same I2C-bus SMBus By NXP Semiconductors